1. Field of the Invention
The present invention generally relates to a motor used for spinning a data storage disk (e.g., CDs and DVDs) detachably arranged in a storage disk drive storing and/or reproducing data onto/from the data storage disk.
2. Description of the Related Art
Recently, a storage disk drive (e.g., a CD drives and a DVD drives) having a reduced axial thickness and a reduced outer dimension, has been called for. To reduce the outer dimension and the axial thickness of the storage disk drive, components of the storage disk drive having a reduced outer dimension and a reduced axial thickness are demanded. As such, it has been led to the desire for a motor used for spinning a data storage disk (e.g., CDs and DVDs) in the storage disk drive, one of the major components of the storage disk drive, to be reduced in its outer dimension and axial thickness.
Recently, packing density of the data storage disk has been increased. Thus, the motor used the data storage disk is demanded to have a high rotational accuracy.
Generally, the motor used for the storage disk drive includes a shaft, a rotor holder attached to the shaft, and a chucking mechanism arranged on the rotor holder to retain the data storage disk on the rotor holder.
Conventionally, in the motor used for spinning the storage disk such as CDs and DVDs in the optical storage disk drive, the shaft and the rotor holder are fixed to each other as follow.
The U.S. Pat. No. 6,700,256 discloses a motor used for spinning a data storage disk such as CDs and DVDs in an optical storage disk drive.
In the motor according to the U.S. Pat. No. 6,700,256, a shaft 1 is press-fitted into a small bore portion 20 positioned in a bore of the projected annular portion 16 of the rotor frame 2 and an adhesive is disposed between the shaft 1 and the rotor frame 2 to connect them. In particular, before the shaft 1 is press-fitted into the small-bore portion 20, an adhesive 22 is preliminarily applied into the large-bore portion 21, and then, the shaft 1 is press-fitted into the small-bore portion 20 of the rotor boss 31 so as to be integrated with each other.
The laid open Japanese patent publication No. 2003-324891 discloses a motor used for an optical disk driving device (e.g., a CD drive and a DVD drive). The motor, illustrated in FIG. 1 of the laid open Japanese patent publication No. 2003-324891, includes a rotor unit having a hub body 40 made of resin and a rotor case 44 and an axially upper portion of a shaft 38 is integrated with the hub body 40.